(1) Field of the Invention
The present invention relates to novel alkane diphosphonic acids and more particularly to novel N-acylated amino alkane diphosphonic acids, to a process of making same, to methods of using same for their sequestering and scale formation preventing effect, and to compositions containing such compounds, said compositions being useful as scale formation preventing agents.
(2) Description of the Prior Art
The most important representative of amino alkane phosphonic acids as they were known heretofore, is the 1-amino ethane-1,1-diphosphonic acid. Said phosphonic acid, however, has the disadvantage that it is difficultly soluble in water and also in alkaline solutions. Due to its low solubility, the 1-amino ethane-1,1-diphosphonic acid is unsuitable for many purposes.
1-AMINO ALKANE- 1,1 -DIPHOSPHONIC ACIDS WHICH ARE SUBSTITUTED AT THE AMINO GROUP, HAVE ALSO BEEN PRODUCED HERETOFORE. One or two hydrogen atoms of the amino group of such compounds have been replaced by alkyl, aralkyl, phenyl, or cycloaliphatic residues. Compounds of this type are, for instance, N-methyl,- or N,N-dimethyl-1-amino ethane-1,1-diphosphonic acids. But said acids are also difficultly soluble like the 1-amino ethane-1,1-diphosphonic acid.